It is known to provide refueling system nozzles of different sizes so that an individual operating the refueling system can be aware of the type of fuel that will be dispensed from the system, and to prevent the inadvertent deposit of a wrong fuel, such as diesel fuel, into some vehicles, such as gasoline powered automobiles. It is known, for example, to provide nozzles for dispensing diesel fuel of a larger diameter than the nozzles for dispensing gasoline or urea. Accordingly, an individual cannot inadvertently dispense diesel fuel from a diesel fuel refueling system into an automobile fuel system requiring gasoline in that an inlet opening at the inlet end of the automobile fuel system will have an opening smaller than the diameter of a diesel fuel dispensing nozzle.
By way of further example, a urea dispensing nozzle commonly has a diameter of 19 mm and a gasoline dispensing nozzle commonly has a diameter of 21 mm. Vehicle fuel systems intended to receive such fuels are provided with fuel system inlet openings only minimally larger than the dispensing nozzle diameter for the fuel intended. Diameters for diesel fuel refueling system dispensing nozzles intended for passenger cars and light trucks are generally between 23.6 mm and 25.5 mm, while high flow rate diesel fuel dispensing nozzles intended for heavy-duty trucks are provided in diameters of 28.5 mm to 38 mm to enable faster dispensing of larger fuel volumes. Again, the inlet openings of vehicle fuel systems intended to be refueled with diesel fuel are provided with opening diameters only minimally larger than the dispensing nozzle diameter from which it is intended to be refueled.
Accordingly, it can be appreciated that the nozzle for diesel fuel dispensing systems generally will not fit into the refueling inlet openings of gasoline or urea fuel systems, and it is therefore unlikely that a fuel system requiring gasoline or urea will be refueled inadvertently with diesel fuel. However, because of the larger diameters at the refueling inlet openings of diesel fuel systems, a vehicle requiring diesel fuel can be refueled inadvertently from a refueling system having a urea dispensing nozzle or a gasoline dispensing nozzle. Refueling with improper fuel can cause damage to fuel systems and engines and therefore must be avoided.
Some nozzle inhibiting structures are known, and can prevent a smaller nozzle from a gasoline or urea refueling system from being inserted into a refueling inlet opening for a diesel fuel system. However, some such known structures are overly complex, complicating assembly, installation or retrofitting on existing systems; as well as compromising performance reliability under some situations. Some are not adequately reliable, and can be forced to admit a smaller nozzle through excessive or angular force applied when trying to insert a smaller nozzle. Accordingly a simple yet reliable structure for inhibiting inadvertent mis-fueling of diesel fuel systems is desirable.